The present invention generally relates to apparatus and methods for testing packages, particularly to apparatus and methods for testing double packages, and more particularly to apparatus and methods for testing sealed liners of double packages.
A common method of packaging cereals, especially Ready-to-Eat cereals, and other foodstuffs is a double package comprising a sealed liner enclosed within a carton. In the past, such liners were formed of glassine or wax paper. However, the use of plastic liners has been increasing because of the advantages obtained thereover. Specifically, plastic liners provide a better moisture seal to the food stuffs being packaged providing extended freshness without staleness. Additionally, plastic liners have a greater tendency to prevent tearing or ripping during manufacturing. A further benefit obtained is that the liner is more consumer friendly allowing the liner to be opened without tearing or ripping and allowing the liner to be resealed by the consumer to preserve freshness. Further, the cost of plastic liners tends to be relatively less than the cost of prior glassine or wax paper liners.
However, one difference between plastic and prior glassine liners is that plastic is structurally more flimsy and has a greater tendency to collapse. Collapse of the liner may disrupt the proper functioning of the remaining packaging operations including but not limited to the filling of foodstuffs into the liner, the dropping of coupons or premiums inside of the liner, closing and sealing the liner, and like operations.
One major source of consumer complaints in the packaging of cereal and other foodstuffs is improperly sealed liners of double packages. Specifically, improperly sealed liners may result in the foodstuff going stale as the result of entrance of moisture into the liner. Even small holes or seal defects can result over time in product going stale prematurely. More serious in terms of consumer perception is a visually apparent opening which can result in the erroneous suspicion of a tampered product. The most prevalent defect in sealing of the liners is an improper sealing of the top of the liner. The collapse of the liner either during forming of the double package, during filling of the foodstuffs into the liner, or during dropping of coupons or premiums inside of the liner, and like operations, is the major cause of improper top sealing. Further, as the top seal is immediately seen when the carton of the double package is initially opened, an improper top seal generates many of the consumer complaints resulting from improperly sealed inner liners. Other defects in the sealing of the liners are improper sealing of the bottom or sides of the liner or holes or tears in the liner itself.
Prior to the present invention, double packages were audited by removing random samples of the double packages at the completion of the packaging operation. It can be appreciated that such audits often did not locate sporadic defective liners because of the relatively small number of samples taken in comparison to the number actually produced and shipped. Further, such audits were often performed at time intervals of 45 minutes or more, such that consistant packaging problems were not noticed or corrected until the audit was performed, potentially resulting in the production of many defective packages. In both cases, defective packages were shipped and ultimately sold to consumers, potentially and justifiably resulting in consumer complaints. Further, as the packaging operation was completed when the audit was performed, the cereal or other foodstuffs in the samples taken could not be reused but were required to be disposed of, resulting in waste of the cereal and foodstuffs even where the samples being tested were properly packaged and marketable before opening.
Accordingly, in the development of the packaging of cereal and other foodstuffs, a need has arisen for testing the liners of double packages to insure that proper sealing has occurred to reduce or practically eliminate the shipment of defective double packages for ultimate sale to the consumer and therefore reduce or practically eliminate consumer complaints resulting from improperly sealed liners inside cartons of the double packages.
Thus, it is an object of the present invention to provide novel apparatus and methods for testing for defective liners in double packages.
Another object of the present invention is to provide such novel apparatus and methods which inspect all packages for defective liners as opposed to only random samples as was performed prior to the present invention.
Yet another object of the present invention is to provide such novel apparatus and methods which allow the ultimate sale of all packages which are tested and found not to include any defects.
Still further, another object of the present invention is to provide such novel apparatus and methods providing immediate feedback so that consistent packaging problems can be located and corrected to minimize the production of defective packages.